This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from an application for PRINTING METHOD FOR IMPROVING PRINTING SPEED earlier filed in the Korean Industrial Property Office on Nov. 6, 1997 and there duly assigned Ser. No. 58302/1997.
1. Technical Field
The present invention relates to a printing method and, more particularly, to a printing method wherein a printer driver and a printer employ the same image compression method so as to enhance printing speed, and wherein image data are compressed using a scanline method and the compressed image data are sent to a printer engine in a printer driver module, whereupon the compressed image data are decompressed in real time and simultaneously printed out in the printer.
2. Related Art
Recently, computers have become suitable for use in multimedia, and users"" documents have become complicated and variable in form due to increasing graphics and hypertexts. Accordingly, a printer with high performance is required to handle a large amount of print data.
In general, printing is performed as explained below. A user gives instruction for printing via an application program, and a host computer converts documents that are to be printed, by means of a printer driver in a host computer, into commands readable by a printer (for example, PCL command for PCL emulation). The converted commands are downloaded to the printer via a serial or parallel port of the host computer.
The printer then interprets the downloaded data, converts data corresponding to one page into bit map data to be readable by the printer, and transmits the same to an engine of the printer so as to perform the printing operation.
When print data are transmitted from a printer driver to a printer, the printer driver compresses image data included in the print data using run-length, tagged image file format (TIFF), or the delta-row method.
Meanwhile, the printer receives the compressed print data and decompresses the data to reproduce the original print data. Then, the printer compresses print data by employing the run-length method, which serves to compress data by word unit. In order to print the compressed print data via a printer engine, the printer decompresses the print data in real-time and transmits that decompressed data to the printer engine.
In the above-described method, print data are compressed and downloaded by a host computer, and a printer decompresses the data and compresses the data again for use in the printer. As a result, printing speed is lowered.
It is, therefore, an object of the present invention to provide a method wherein a host computer and a printer employ the same compression method so that data need not be compressed twice.
It is an additional object of the present invention to provide a method wherein image data are compressed using a scanline method and the compressed image data are sent to a printer engine in a printer driver module, whereupon the compressed image data are decompressed in real time and simultaneously printed out in the printer.
According to one aspect of the present invention, there is provided a printing method for improving printing speed, including the steps of: transmitting print data to a printer driver; compressing the transmitted print data using a first method and downloading the print data to a printer; and decompressing the downloaded print data using the above-mentioned first method and printing the same.
Preferably, the scanline method is employed as the first method, and the decompression is performed in real-time.
According to another aspect of the present invention, there is provided a printing method for improving printing speed, including the steps of: transmitting print data from a host computer to a printer driver; classifying the received data into image data and text data; compressing the image data using a first method, font-mapping the text data, and downloading the image and text data to a printer; decompressing the downloaded image data in real-time by employing the first method, transmitting font information of the text data, and printing the image and text data.
Again, preferably, the scanline method is employed as the first method.